Silicon Nitride Waveguide Technology: TriPleX®
Silicon nitride(SiN) TriPleX® is our proprietary waveguide technology for photonic integrated circuits (PICs). LioniX International has been pioneering the use of silicon nitride in integrated photonics since 2001 and has an extensive library of building blocks for both photonic integrated circuit design and module development.
TriPleX® waveguides have the lowest propagation losses reported in SiN (0.1 dB/cm down to 0.1 dB/m). Silicon nitride waveguides are suitable for a wide range of photonic integrated circuit applications, operating in a broad wavelength band from 405 nm to 2350 nm.
Silicon nitride waveguide TriPleX® journal article:
Get an in-depth look at the strengths and applications of the TriPleX® waveguide platform.
Different waveguide cross-sections showing silicon nitride waveguide in silicon oxide substrate.
TriPleX® waveguide structure
TriPleX® waveguides come in different cross sections (left). The cross sections range between box shapes, single stripe, and double stripes. The latter coming in two forms; the symmetric double stripe and the asymmetric double stripe (ADS). Finally the TriPleX® family has a buried waveguide for very thick nitride layers.
Double stripe silicon nitride
Each of these cross sections have different properties optimized for use in a specific application: The asymmetric double stripe cross section is our workhorse at 1550 nm applications and is offered as well via our multi project wafer (MPW) services. The losses of this waveguide are < 0.1 dB/cm and with the taper the fiber coupling losses are below 0.5 dB per facet.
Ultra low-loss waveguides
The single stripe version of TriPleX® is used for ultra low loss applications (losses as low as 0.1 dB/meter) or in applications in the visible light domain. In the visible domain the single stripe is optimized for fiber coupling as well low loss propagation of the wavelengths between 405 to 700nm.
Waveguides engineered for integration
As a low loss passive waveguide material, silicon nitride has no native light generating capability. LioniX International solve this by engineering TriPleX® waveguides for excellent input and output coupling (to fibers, gratings, mirrors and other PICs), enabling integration with a wide range of optimized components for light generation, modulation and detection. We call this approach to photonic module design “hybrid integration” and it underpins higher levels of functionality in a great range of photonic integrated circuit applications including:
- Integrated optical beamforming and filtering modules
- Hybrid integrated tunable lasers
- Optical phased arrays
- Integrated biosensor chips
In order to enable this high level of integration, LioniX International has developed a patented tapering method to convert low contrast modes for optimal fiber coupling, to high contrast modes for small bending radii. This novel building block, known as a spot size converter, further extends the applicability of TriPleX® waveguides to devices that require high levels of integration and highly optimized performance.
A hybrid integrated dual gain laser with indium phosphide gain sections (gold) and a silicon nitride tunable external cavity (grey).
MPW: Easy access for silicon nitride photonic waveguide technology
Multi Project Wafer (MPW) runs provide cost-effective easy access to TriPleX® waveguides. Design photonic integrated circuits using freely available process design kits (PDKs) and qualified standard building blocks.